Problem: $ { {2} \times \left[\begin{array}{rr}{2} & {-2} \\ {3} & {1}\end{array}\right] = {?} } $
To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rr}{2}\times{2} & {2}\times{-2} \\ {2}\times{3} & {2}\times{1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{4} & {-4} \\ {6} & {2}\end{array}\right]}$